Lubricant



No Drawing.

to start in cold Patented July 21, 1925.

UNITED STATES 1 1,547,141 PATENT OFFICE.

ROBERT E. WILSON, OF CHICAGO, ILLINOIS, ASSIG-NOB TO STANDARD OIL COMPANY,

OF WHITING, INDIANA, A CORPORATION OF INDIANA.

LUBRICANT.

To all whom it may concern:

Be it known that I, ROBERT E. WILSON, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a new and useful Improvement in Lubricants, of which the following is a specification.

This invention consists in a new lubricantfor automotive engines, a lubricant particularly adapted for use in cold weather in engines of the usual type wherein more or less .fuel enters the lubricant in the crank case.

Heretofore there have been in use three broad types of lubricating oil which may be the heavier fractions of the fuel,which, par

ticularly when the motor is cold, leak past the piston rings and enter the oil body in the crank case.

There are serious objections to oils of each of the three types now in common use. Heavy oil is so viscous when freshly renewed in the motor as to make starting a cold motor altogether too difficult, and for this reason heavy oil is seldom used in winter. Medium oil is open to the same objection but to a lesser extent, and while it is very largely used as a winter lubricant, it is so viscous when cold and fresh as to throw a very heavy and undesirable load on the starting motor and battery and when highly diluted is too fluid to lubricate properly. Light oil, on the other hand, while far superior to the other grades from the standpoint of ease of starting when cold and fresh, loses viscosity by dilution so fast as to be a very poor lubricant frequently in less than a hundred miles of driving.

The preferred oil of those within my invention is,,when cold and fresh, slightly less viscous than the general run of the light oils when fresh and it is therefore very easy weather. Nevertheless the new lubricant practically loses no viscosity by dilution, in an. average car in good condition and with proper carbureter adjustment in ordinary winter operation. Thus,

Application filed January 15, 1925. Serial No. 2,686.

dium after five hundred miles of winter use.

While the properties of the preferred oil within myinvention have been set forth, it will be evident that it is not necessary to utilize the full benefit of the invention, for

the advantage of easy starting with fresh lubricant can be obtained even though the oil be of a type giving a viscosity, after long use, generally similar to that of the medium oil now generally used. In general the new lubricant. is characterized by apractically horizontal curve of viscosity plotted against mileage, and hence has, for any given initial viscosity, a very high final viscosity. It is further distinguishable by being a clean marketable oil, free from suspended solids and colloidal carbon or asphalt and from noticeable disagreeable odor, and having a fiash'point above 150 F.

The preferred oil has a Saybolt viscosity at 100 F. of about 180, and on distillation gives an intial boiling point (thermometer in vapor) of about 350 F. and about 11% off at 460 F. The fractionation of the oil may, of course, vary considerably, but in general it should contain from about 6% .to about 15% of fractions boiling between 300 F. and 460 F., and should have a Saybolt viscosity at 100 F. above 140.

As illustrative of one example in the practice of my invention in the case of ,paraflin type oil (including mid-continent oil), the remaining 85 to 94% may suitably be a viscous lubricant oil, having a viscosity of 425 to 475 sec. Saybolt at 100 F. Thus, with 89 parts by volume of' a lubricant oil of 450 sec. Saybolt, at 100 F. there is combined 11% of light distillate having a boiling point range of 350 to 460 F., there by providing a product having the advantages and characteristics above set forth.

.I claim:

1. The herein described marketable lubricating oil for cold weather use in automoloidal carbon and marked disagreeable odor,

- and characterized further by having a flash point above 150 F., a Saybolt viscosity of at least 140 at 100 F., a relatively low loss in viscosity during'use, and a content of between 7% and 15% of fractions boiling be- 10 tween about 300 F. and 460 F.

2. The herein described marketable lubrie cylinders, clear in I appearance, free from suspended solids, colappearance, free from suspended solids,

colloidal carbon and marked disagreeable odor, and characterized further in having an initial boiling point of 350 vF., a Sayboltviscosity of 180 at 100 F., a slight loss in viscosity during use, and about 11% of fractions boiling below 460.F.

' ROBERT WILSON. 

